Flatworm
Fig. 43: A swimming flatworm with a lot of transprarent other worms swimming always in the light beam of my camera. Dive #407: Night dive in Radi Harbour, Fiji. — EXIF: Nikon D200; Δt=1/200 s; f=60 mm; f/16.0; ISO 100; 2010-08-11 7:58:11